vac leak

[redwoody]

fresh 360. I have vac pump and cheked all vac lines. New EGR. Used full can of gum out around intake and base of carb. Checked line to vacuum booster. My transfer vacuum operates 4x4. adv vac holds. Just mild rv cam and my builder says I should be at 20 in vac. At cold start 13.5 warms to around 16 to 17 and fluctuates. 2150 carb has been cleaned and rebuilt. Im guessing internal carb leak? Thx

[lkmarsh]

Did you disconnect vacuum line to brake booster and plug it?
Vacuum ball cracked? Stuck pcv? Vacuum lines under the dash?
Split rubber cap on an unused vacuum port?
You can check a brake booster with a vacuum pump but it takes forever.


Worst leak I ever dealt with was vacuum canister split a seam.
Took two weeks to find it.

[redwoody]

vacuum ball and under dash Thx. Did ck booster by removing line and plugging no change on vac guage

[PBG928]

Check two lines on passenger side of engine that vent fuel tank. Plug temporarily and see if performance improves.

[Crankyolman]

You say you are running a 2150, by chance could you have used a 2100 base gasket?

[redwoody]

my charcoal can is all plugged off. Vac lines have been removed. Theres no response using carb cleaner at base of carb. I just purchased the gskt under spacer for 2150. Pcv is clean and moves. Thx

[babywag]

My 90 has what I believe to be an rv cam installed.
It isn't a stocker but no idea what is installed.
It has never idled with higher than ~17" of vacuum.
A stock cam would do higher vacuum, 17 sounds normal to me.

If vacuum is fluctuating it could be AFR or ignition issues.
Or a mechanical issue

[redwoody]

Took wag to builder. He replaced my pcv (was intermittent) w/ Dodge 360 set up. Don't need formed hose to base of carb. also my trap door in air cleaner(vac motor) was not opening fully. Hope this helps others. thx